The iButton® is a 16-millimeter computer chip with a unique ID number enclosed in a stainless steel container. Each chip’s ID number is unaffected by magnetic fields, metal detectors, water, and most common chemicals.
Technically, an iButton is technically the round stainless steel “container” at the end of your black plastic keyfob. You can drop it, step on it, scratch it or wear it swimming.
What’s in that container? All that’s in there is a tiny electronic chip. But that chip is more powerful than it appears: When you tap your iButton to the iButton probe on your timeclock, the chip transmits its unique serial number to the clock. That serial number is 16 characters long and has 72,057,594,037,927,936 possible combinations.
When you set up your iButtons in the TimePilot software, the name of each employee was linked to the serial number of his or her iButton. That’s how the system knows who you are when you clock in or out.
TimePilot’s clocks use the simplest kind of iButton; there are others that remember data, keep track of time and even keep a record of temperature and humidity.